Convert the mixed repeating (recurring) decimal number 0.39. Turn it into a reduced (simplified) proper fraction and write it as a percentage. Equivalent fractions calculator

Convert 0.39 into equivalent fractions and write it as a percentage value

1. Write the mixed repeating (recurring) decimal number as a percentage.

Approximate to the desired number of decimal places.

0.39 ≈ 0.4


Multiply the number by 100/100.

  • The value of the number does not change when multiplying by 100/100.
  • Note: 100/100 = 1

0.4 =

0.4 × 100/100 =

(0.4 × 100)/100 =

40/100 =

40%


  • In other words:
  • Approximate to the desired number of decimal places...
  • Multiply the number by 100...
  • ... And then add the percent sign, %
  • 0.39 ≈ 40%

» Convert fractions to percentages, online calculator


2. Write the mixed repeating (recurring) decimal number as a proper fraction.

  • 0.39 can be written as a proper fraction.

  • The numerator is smaller than the denominator.

Set up the first equation.

  • Let y equal the decimal number:

  • y = 0.39


Set up the second equation.

  • Number of decimal places repeating: 1

  • Multiply both sides of the first equation by 101 = 10


y = 0.39

10 × y = 10 × 0.39

10 × y = 3.9

Get the same number of decimal places as for y:

10 × y = 3.99

Note: 3.99 = 3.9


Subtract the first equation from the second one.

  • Having the same number of decimal places ...
  • The repeating pattern drops off by subtracting the two equations.

10 × y - y = 3.99 - 0.39 ⇒

(10 - 1) × y = 3.99 - 0.39 ⇒

We now have a new equation:

9 × y = 3.6


Solve for y in the new equation.

9 × y = 3.6 ⇒

y = 3.6/9

Let the result written as a fraction.



Now we can write the number as a fraction.

According to our first equation:

y = 0.39

According to our calculations:

y = 3.6/9

⇒ 0.39 = 3.6/9


Get rid of the decimal places in the fraction above.

  • Multiply the top and the bottom number by 10.
  • 1 followed by as many 0-s as the number of digits after the decimal point.

0.39 = (3.6 × 10)/(9 × 10)

0.39 = 36/90


3. Reduce (simplify) the fraction above:
36/90
to the lowest terms, to its simplest equivalent form, irreducible.

To reduce a fraction to the lowest terms divide the numerator and denominator by their greatest (highest) common factor (divisor), GCF.


Factor the numerator and denominator (prime factorization).

36 = 22 × 32

90 = 2 × 32 × 5


» Prime factorization: break numbers down to prime factors, online calculator


Calculate the greatest (highest) common factor (divisor), GCF.

Multiply all the common prime factors by the lowest exponents.

GCF (22 × 32; 2 × 32 × 5) = 2 × 32


» Calculate the greatest (highest) common factor (divisor), GCF, online calculator


Divide both the numerator and the denominator by their GCF.

36/90 =

(22 × 32)/(2 × 32 × 5) =

((22 × 32) ÷ (2 × 32)) / ((2 × 32 × 5) ÷ (2 × 32)) =

2/5


2/5 ~ Equivalent fractions.

  • The above fraction cannot be reduced.
  • That is, it has the smallest possible numerator and denominator.

  • By expanding it we can build up equivalent fractions.

  • Multiply the numerator & the denominator by the same number.


Example 1. By expanding the fraction by 5.

2/5 = (2 × 5)/(5 × 5) = 10/25

Example 2. By expanding the fraction by 9.

2/5 = (2 × 9)/(5 × 9) = 18/45

  • Of course, the above fractions are reducing...
  • ... to the initial fraction: 2/5

» Reduce fractions and write them as decimal numbers and percentages


:: Final answer ::
Written in 3 different ways

As a reduced (simplified) positive proper fraction:
0.39 = 2/5

As a percentage:
0.39 = 40%

As equivalent fractions:
0.39 = 2/5 = 10/25 = 18/45

More operations of this kind

0.4 = ? Convert the pure repeating (recurring) decimal number 0.4. Turn it into a reduced (simplified) proper fraction and write it as a percentage. Calculate other equivalent fractions to the decimal number, by expanding

Decimal numbers to fractions and percentages, calculator

Learn how to turn a decimal number into a fraction and a percentage. Steps.

1. How to write the number as a percentage:

  • Multiply the number by 100. Then add the percent sign, %.

2. How to write the number as a fraction:

  • Write down the number divided by 1, as a fraction.
  • Turn the top number into a whole number: multiply both the top and the bottom by the same number.
  • Reduce (simplify) the above fraction to the lowest terms, to its simplest equivalent form, irreducible. To reduce a fraction divide the numerator and the denominator by their greatest (highest) common factor (divisor), GCF.
  • If the fraction is an improper one, rewrite it as a mixed number (mixed fraction).
  • Calculate equivalent fractions. By expanding it we can build up equivalent fractions: multiply the numerator & the denominator by the same number.

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